A description of a system to allow non-dynamic phasing of cam lobes is given by Goracy in U.S. Pat. No. 7,036,473 B1, which is hereby incorporated by reference for all that is taught and disclosed therein.
Numerous inventors have patented dynamic systems of valve actuation, focusing either on the rocker arm (e.g. Honda, U.S. Pat. No. 4,788,946, Porsche, U.S. Pat. No. 5,603,293) or on the lifter (GM, U.S. Pat. Nos. 6,557,518, 7,503,296). U.S. Pat. No. 4,788,946, the inventors describe a means of locking components of multiple piece rocker arms together to allow operation of specific cam lobes (low lift, low duration, or high lift, high duration) on a single valve. In the case of U.S. Pat. No. 7,503,296 the inventors show a collapsing follower that may be made rigid dynamically, allowing actuation of the connected valve when desired, or allowing the valve to remain closed when desired.